[09/23] powerpc: Remove _dl_var_init

  The generic __rtld_static_init code handles GLRO (dl_pagesize),
GLRO (dl_auxv), GLRO (dl_hwcap), GLRO (dl_hwcap2).
GLRO (dl_cache_line_size) is handled in an __rtld_static_init_arch
override.
---
 sysdeps/unix/sysv/linux/powerpc/Makefile      |  4 -
 sysdeps/unix/sysv/linux/powerpc/Versions      |  6 --
 sysdeps/unix/sysv/linux/powerpc/dl-static.c   | 96 -------------------
 .../{ldsodefs.h => rtld_static_init.h}        | 26 ++---
 4 files changed, 10 insertions(+), 122 deletions(-)
 delete mode 100644 sysdeps/unix/sysv/linux/powerpc/dl-static.c
 rename sysdeps/unix/sysv/linux/powerpc/{ldsodefs.h => rtld_static_init.h} (59%)
  

On 12/05/2021 13:58, Florian Weimer via Libc-alpha wrote:
> The generic __rtld_static_init code handles GLRO (dl_pagesize),
> GLRO (dl_auxv), GLRO (dl_hwcap), GLRO (dl_hwcap2).
> GLRO (dl_cache_line_size) is handled in an __rtld_static_init_arch
> override.

LGTM.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

> ---
>  sysdeps/unix/sysv/linux/powerpc/Makefile      |  4 -
>  sysdeps/unix/sysv/linux/powerpc/Versions      |  6 --
>  sysdeps/unix/sysv/linux/powerpc/dl-static.c   | 96 -------------------
>  .../{ldsodefs.h => rtld_static_init.h}        | 26 ++---
>  4 files changed, 10 insertions(+), 122 deletions(-)
>  delete mode 100644 sysdeps/unix/sysv/linux/powerpc/dl-static.c
>  rename sysdeps/unix/sysv/linux/powerpc/{ldsodefs.h => rtld_static_init.h} (59%)
> 
> diff --git a/sysdeps/unix/sysv/linux/powerpc/Makefile b/sysdeps/unix/sysv/linux/powerpc/Makefile
> index a093cda68b..06f1328fab 100644
> --- a/sysdeps/unix/sysv/linux/powerpc/Makefile
> +++ b/sysdeps/unix/sysv/linux/powerpc/Makefile
> @@ -13,10 +13,6 @@ gen-as-const-headers += ucontext_i.sym
>  endif
>  
>  ifeq ($(subdir),elf)
> -ifeq ($(build-shared),yes)
> -# This is needed for DSO loading from static binaries.
> -sysdep-dl-routines += dl-static
> -endif
>  # Otherwise tst-tls-dlinfo fails due to tst-tlsmod2.so using static tls.
>  LDFLAGS-tst-tlsmod2.so += -Wl,--no-tls-get-addr-optimize
>  endif

Ok.

> diff --git a/sysdeps/unix/sysv/linux/powerpc/Versions b/sysdeps/unix/sysv/linux/powerpc/Versions
> index cc28d84744..416272b718 100644
> --- a/sysdeps/unix/sysv/linux/powerpc/Versions
> +++ b/sysdeps/unix/sysv/linux/powerpc/Versions
> @@ -1,9 +1,3 @@
> -ld {
> -  GLIBC_PRIVATE {
> -  # used for loading by static libraries
> -    _dl_var_init;
> -  }
> -}
>  libc {
>    GLIBC_PRIVATE {
>      __vdso_get_tbfreq;

Ok.

> diff --git a/sysdeps/unix/sysv/linux/powerpc/dl-static.c b/sysdeps/unix/sysv/linux/powerpc/dl-static.c
> deleted file mode 100644
> index e35ca4c44b..0000000000
> --- a/sysdeps/unix/sysv/linux/powerpc/dl-static.c
> +++ /dev/null
> @@ -1,96 +0,0 @@
> -/* Variable initialization.  PowerPC version.
> -   Copyright (C) 2013-2021 Free Software Foundation, Inc.
> -   This file is part of the GNU C Library.
> -
> -   The GNU C Library is free software; you can redistribute it and/or
> -   modify it under the terms of the GNU Lesser General Public
> -   License as published by the Free Software Foundation; either
> -   version 2.1 of the License, or (at your option) any later version.
> -
> -   The GNU C Library is distributed in the hope that it will be useful,
> -   but WITHOUT ANY WARRANTY; without even the implied warranty of
> -   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> -   Lesser General Public License for more details.
> -
> -   You should have received a copy of the GNU Lesser General Public
> -   License along with the GNU C Library.  If not, see
> -   <https://www.gnu.org/licenses/>.  */
> -
> -#include <ldsodefs.h>
> -
> -#ifdef SHARED
> -
> -void
> -_dl_var_init (void *array[])
> -{
> -  /* It has to match "variables" below. */
> -  enum
> -    {
> -      DL_PAGESIZE = 0,
> -      DL_AUXV = 1,
> -      DL_HWCAP = 2,
> -      DL_HWCAP2 = 3,
> -      DL_CACHE_LINE_SIZE = 4
> -    };
> -
> -  GLRO(dl_pagesize) = *((size_t *) array[DL_PAGESIZE]);
> -  GLRO(dl_auxv) = (ElfW(auxv_t) *) *((size_t *) array[DL_AUXV]);
> -  GLRO(dl_hwcap)  = *((unsigned long int *) array[DL_HWCAP]);
> -  GLRO(dl_hwcap2) = *((unsigned long int *) array[DL_HWCAP2]);
> -  GLRO(dl_cache_line_size) = (int) *((int *) array[DL_CACHE_LINE_SIZE]);
> -}
> -
> -#else
> -
> -static void *variables[] =
> -{
> -  &GLRO(dl_pagesize),
> -  &GLRO(dl_auxv),
> -  &GLRO(dl_hwcap),
> -  &GLRO(dl_hwcap2),
> -  &GLRO(dl_cache_line_size)
> -};
> -
> -static void
> -_dl_unprotect_relro (struct link_map *l)
> -{
> -  ElfW(Addr) start = ((l->l_addr + l->l_relro_addr)
> -		      & ~(GLRO(dl_pagesize) - 1));
> -  ElfW(Addr) end = ((l->l_addr + l->l_relro_addr + l->l_relro_size)
> -		    & ~(GLRO(dl_pagesize) - 1));
> -
> -  if (start != end)
> -    __mprotect ((void *) start, end - start, PROT_READ | PROT_WRITE);
> -}
> -
> -void
> -_dl_static_init (struct link_map *l)
> -{
> -  struct link_map *rtld_map = l;
> -  struct r_scope_elem **scope;
> -  const ElfW(Sym) *ref = NULL;
> -  lookup_t loadbase;
> -  void (*f) (void *[]);
> -  size_t i;
> -
> -  loadbase = _dl_lookup_symbol_x ("_dl_var_init", l, &ref, l->l_local_scope,
> -				  NULL, 0, 1, NULL);
> -
> -  for (scope = l->l_local_scope; *scope != NULL; scope++)
> -    for (i = 0; i < (*scope)->r_nlist; i++)
> -      if ((*scope)->r_list[i] == loadbase)
> -	{
> -	  rtld_map = (*scope)->r_list[i];
> -	  break;
> -	}
> -
> -  if (ref != NULL)
> -    {
> -      f = (void (*) (void *[])) DL_SYMBOL_ADDRESS (loadbase, ref);
> -      _dl_unprotect_relro (rtld_map);
> -      f (variables);
> -      _dl_protect_relro (rtld_map);
> -    }
> -}
> -
> -#endif

Ok.

> diff --git a/sysdeps/unix/sysv/linux/powerpc/ldsodefs.h b/sysdeps/unix/sysv/linux/powerpc/rtld_static_init.h
> similarity index 59%
> rename from sysdeps/unix/sysv/linux/powerpc/ldsodefs.h
> rename to sysdeps/unix/sysv/linux/powerpc/rtld_static_init.h
> index bb9c262299..730ac19f77 100644
> --- a/sysdeps/unix/sysv/linux/powerpc/ldsodefs.h
> +++ b/sysdeps/unix/sysv/linux/powerpc/rtld_static_init.h
> @@ -1,6 +1,5 @@
> -/* Run-time dynamic linker data structures for loaded ELF shared objects.
> -   PowerPC version.
> -   Copyright (C) 2013-2021 Free Software Foundation, Inc.
> +/* Partial initialization of ld.so loaded via static dlopen.  powerpc helper.
> +   Copyright (C) 2021 Free Software Foundation, Inc.
>     This file is part of the GNU C Library.
>  
>     The GNU C Library is free software; you can redistribute it and/or
> @@ -17,17 +16,12 @@
>     License along with the GNU C Library; if not, see
>     <https://www.gnu.org/licenses/>.  */
>  
> -#ifndef _LDSODEFS_H
> +static inline void
> +__rtld_static_init_arch (struct link_map *map, struct rtld_global_ro *dl)
> +{
> +  /* This field does not exist in the generic _rtld_global_ro version.  */
>  
> -/* Get the real definitions.  */
> -#include_next <ldsodefs.h>
> -
> -/* Now define our stuff.  */
> -
> -/* We need special support to initialize DSO loaded for statically linked
> -   binaries.  */
> -extern void _dl_static_init (struct link_map *map);
> -#undef DL_STATIC_INIT
> -#define DL_STATIC_INIT(map) _dl_static_init (map)
> -
> -#endif /* ldsodefs.h */
> +  extern __typeof (dl->_dl_cache_line_size) _dl_cache_line_size
> +    attribute_hidden;
> +  dl->_dl_cache_line_size = _dl_cache_line_size;
> +}
> 

Ok.